libcurl 通过http协议下载文件并显示下载进度

vc6 测试工程下载地址： http://download.csdn.net/detail/mtour/8068053

代码如下：

size_t my_write_func(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
  return fwrite(ptr, size, nmemb, stream);
}

int my_progress_func(char *progress_data,
                     double t, /* dltotal */
                     double d, /* dlnow */
                     double ultotal,
                     double ulnow)
{
  printf("%s %g / %g (%g %%)
", progress_data, d, t, d*100.0/t);
  return 0;
}

int main(int argc, char **argv)
{
  CURL *curl;
  CURLcode res;
  FILE *outfile;
  char *url = "http://10.10.1.4/d/c00000000000039/2014-10-22/10-28-35.ps";
  char *progress_data = "* ";

  curl = curl_easy_init();
  if(curl)
  {
    outfile = fopen("test.ps", "wb");

    curl_easy_setopt(curl, CURLOPT_URL, url);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, outfile);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, my_write_func);
    curl_easy_setopt(curl, CURLOPT_NOPROGRESS, FALSE);
    curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, my_progress_func);
    curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, progress_data);

    res = curl_easy_perform(curl);

    fclose(outfile);
    /* always cleanup */
    curl_easy_cleanup(curl);
  }
  return 0;
}